Machine for screening or sifting coal



UNITED STATES PATENT OFFICE.

BENJN. S. HORT, OF KENSINGTON, PENNSYLVANIA.

MACHINE FOR SCREENING 0R SIFTING- COAL.

Specification of Letters Patent No. 2,451, dated February 7, 1842.

To all 'wh-0112. Z5 may concern.'

Be it known that I, BENJAMIN S. Hour, of Kensington, in the county ofPhiladelphia and State of Pennsylvania, have made a new and usefulimprovement in the manner ot constructing a revolving single-cylinderscreen for screening hard coal, gravel, and other' substances requiringto be separated into parcels varying in size from each other; and I dohereby declare that the following is a full and eXactdescriptionthereof.

In the accompanying drawing, A, A, is a single cylinder screen, which isconstructed of hoops and rods of iron, or otherwise, not necessarilydiiiering, in this respect, from the screens now in use. The dimensionsof the meshes must. be governed by the use to which the screen is put;when used for coal, the part A, will have openings which will allow whatis usually called broken coal to pass through; the part A, openingsadapted to egg coal; the part A2, to nut coal, and the part A3, to limeburning, or fine, coal. In such cylindrical screens as have heretoforebeen constructed, the coal has been mace to pass through them by givinga su'fcient degree of inclination to the instrument to effect thatobject; but the screen as constructed by me is to be placedhorlzontally, or nearly so, and the coal which is fed in at one end isto be carried toward the other by means of a spiral thread, which may bemade of sheet iron, and the outer edge of which is in contact with themeshes of the screen; this spiral thread is seen at, a, a., a, in thedrawings. The threads may be placed at any required distance apart, andthe coal is, ot course, to be fed in at that end which has the finermeshes; and when the screen is made to revolve in the proper direction,the coal will be carried toward the opposite end by an equable motion,which is not the case with the screen as usually constructed with acontinuous cylinder, and without a spiral thread, the action of such ascreen being, in this respect, very different with wet, and with dry,coal, as well as with other articles, either from the same, or other,causes.

Having thus fully described the nature of my improvement in therevolving, single, cylinder screen, for screening hard coal, and otherarticles, what I claim therein as new, and desire to secure by LettersPatent, is-

The combining of a spiral thread of sheet metal, or other suitablesubstance, with such a screen, in the manner herein set forth, by whichcombination it is made to operate in a horizontal position, and thematerial to be screened is carried along the cylinder with a measuredvelocity, depending upon the closeness of t-he threads of the screen,and the rapidity with which said cylinder is turned.

BENJN. S. HORT.

Titnesses Tiros. P. JONES, M. E. JONES.

